Toward Rational Functionalization of Ionic Liquids for Enhanced Extractive Desulfurization: Computer-Aided Solvent Design and Molecular Dynamics Simulation

Although
functionalization is known as a promising way to notably
improve the performances of ionic liquids (ILs) in separation processes,
studies thereon are mainly based on experimental trial and error while
rational design of functional ILs is scarcely reported. In this work,
computer-aided IL design (CAILD) and molecular dynamics (MD) simulation
are combined toward rationally functionalizing ILs for the enhanced
extractive desulfurization (EDS) of fuel oils. First, the UNIFAC-IL
model is extended based on experimental data to specifically cover
interaction parameters associated with four functional groups (i.e.,
hydroxyl, methoxy, vinyl, and cyanomethyl). A mixed-integer nonlinear
programming problem is then formulated for the computer-aided design
of functional ILs for the EDS task. Finally, MD simulations are performed
to study the intermolecular interactions between the top IL candidates
and model fuel oil components; compared with those for literature-reported
ILs, the enhanced EDS performances of the designed functional ILs
are well rationalized.